<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="/static/js/jquery-3.1.1.min.js"></script>
</head>
<body>

<button class="btn" id="btn">aaa</button>
<table class="tab" id="tab">
    <tr>
        <td>1</td><td>2</td>3<td>4</td>
    </tr>
    <tr>
        <td>1</td><td>2</td>3<td>4</td>
    </tr>
</table>
<script>
    $(".btn").click(function () {
        console.log("触发了点击事件");
    })
</script>
</body>
</html>